“ The term " spy " is applied also to those who in time of peace secretly endeavour to obtain information concerning the forces, armaments, fortifications or defences of a country for the purpose of supplying it to another country. Every country has always endeavoured to guard jealously its military and naval secrets, and with this object denies admittance to fortified places or arsenals to those who cannot produce the proper credentials. ”

“ A soldier not wearing a disguise is not a spy, though he may be found within the zone of the hostile army and though his object may be to obtain information; nor are soldiers or civilians spies who cross enemy lines openly carrying messages. ”